/*
 SelectFilter2 - Turns a multiple-select box into a filter interface.

 Different than SelectFilter because this is coupled to the admin framework.

 Requires core.js and OrderedSelectBox.js
 */

function findForm(node) {
    // returns the node of the form containing the given node
    if (node.tagName.toLowerCase()  != 'form') {
        return findForm(node.parentNode);
    }
    return node;
}

var OrderedSelectFilter = {
    init: function(field_id, field_name, is_stacked) {
        if (field_id.match(/__prefix__/)){
            // Don't intialize on empty forms.
            return;
        }

        var from_box = document.getElementById(field_id);

        if(!from_box) {
          return;
        }

        from_box.id += '_from'; // change its ID
        from_box.className = 'filtered';

        var ps = from_box.parentNode.getElementsByTagName('p');
        for (var i=0; i<ps.length; i++) {
            if (ps[i].className.indexOf("info") != -1) {
                // Remove <p class="info">, because it just gets in the way.
                from_box.parentNode.removeChild(ps[i]);
            } else if (ps[i].className.indexOf("help") != -1) {
                // Move help text up to the top so it isn't below the select
                // boxes or wrapped off on the side to the right of the add
                // button:
                from_box.parentNode.insertBefore(ps[i], from_box.parentNode.firstChild);
            }
        }

        // <div class="selector"> or <div class="selector stacked">
        var selector_div = quickElement('div', from_box.parentNode);
        selector_div.className = is_stacked ? 'selector stacked' : 'selector';

        // <div class="selector-available">
        var selector_available = quickElement('div', selector_div, '');
        selector_available.className = 'selector-available';
        var title_available = quickElement('h2', selector_available, interpolate(gettext('Available %s') + ' ', [field_name]));
        quickElement(
                'span', title_available, '',
                'class', 'help help-tooltip help-icon',
                'title', interpolate(
                    gettext(
                        'This is the list of available %s. You may choose some by ' +
                        'selecting them in the box below and then clicking the ' +
                        '"Choose" arrow between the two boxes.'
                    ),
                    [field_name]
                )
            );

        var filter_p = quickElement('p', selector_available, '');
        filter_p.className = 'selector-filter';

        var search_filter_label = quickElement('label', filter_p, '', 'for', field_id + '_input');

        quickElement(
                'span', search_filter_label, '',
                'class', 'help-tooltip search-label-icon',
                'title', interpolate(gettext("Type into this box to filter down the list of available %s."), [field_name])
            );

        filter_p.appendChild(document.createTextNode(' '));

        var filter_input = quickElement('input', filter_p, '', 'type', 'text');
        filter_input.id = field_id + '_input';
        selector_available.appendChild(from_box);
        var choose_all = quickElement('a', selector_available, gettext('Choose all'), 'title', gettext('Choose all'), 'href', '#', 'id', field_id + '_add_all_link');
        choose_all.className = 'selector-chooseall';

        // <ul class="selector-chooser">
        var selector_chooser = quickElement('ul', selector_div);
        selector_chooser.className = 'selector-chooser';
        var add_link = quickElement('a', quickElement('li', selector_chooser), gettext('Choose'), 'title', gettext('Choose'), 'href', '#', 'id', field_id + '_add_link');
        add_link.className = 'selector-add';
        var remove_link = quickElement('a', quickElement('li', selector_chooser), gettext('Remove'), 'title', gettext('Remove'), 'href', '#', 'id', field_id + '_remove_link');
        remove_link.className = 'selector-remove';

        // <div class="selector-chosen">
        var selector_chosen = quickElement('div', selector_div, '');
        selector_chosen.className = 'selector-chosen';
        var title_chosen = quickElement('h2', selector_chosen, interpolate(gettext('Chosen %s') + ' ', [field_name]));
        quickElement(
                'span', title_chosen, '',
                'class', 'help help-tooltip help-icon',
                'title', interpolate(
                    gettext(
                        'This is the list of chosen %s. You may remove some by ' +
                        'selecting them in the box below and then clicking the ' +
                        '"Remove" arrow between the two boxes.'
                    ),
                    [field_name]
                )
            );

        var to_box = quickElement('select', selector_chosen, '', 'id', field_id + '_to', 'multiple', 'multiple', 'size', from_box.size, 'name', from_box.getAttribute('name'));
        to_box.className = 'filtered';
        var clear_all = quickElement('a', selector_chosen, gettext('Remove all'), 'title', gettext('Clear all'), 'href', '#', 'id', field_id + '_remove_all_link');
        clear_all.className = 'selector-clearall';

        // <ul class="selector-chooser">
        var selector_chooser = quickElement('ul', selector_div);
        selector_chooser.className = 'selector-chooser';
        var up_link = quickElement('a', quickElement('li', selector_chooser, ''), gettext('Up'), 'href', 'javascript: (function(){ OrderedSelectBox.orderUp("' + field_id + '_to");})()');
        up_link.className = 'selector-up';
        var down_link = quickElement('a', quickElement('li', selector_chooser, ''), gettext('Down'), 'href', 'javascript: (function(){ OrderedSelectBox.orderDown("' + field_id + '_to");})()');
        down_link.className = 'selector-down';


        from_box.setAttribute('name', from_box.getAttribute('name') + '_old');

        // Set up the JavaScript event handlers for the select box filter interface
        var move_selection = function(e, elem, move_func, from, to) {
            if (elem.className.indexOf('active') !== -1) {
                move_func(from, to);
                OrderedSelectFilter.refresh_icons(field_id);
            }
            e.preventDefault();
        };
        choose_all.addEventListener('click', function(e) {
                move_selection(e, this, OrderedSelectBox.move_all, field_id + '_from', field_id + '_to');
            });
        add_link.addEventListener('click', function(e) {
            move_selection(e, this, OrderedSelectBox.move, field_id + '_from', field_id + '_to');
        });
        remove_link.addEventListener('click', function(e) {
            move_selection(e, this, OrderedSelectBox.move, field_id + '_to', field_id + '_from');
        });
        clear_all.addEventListener('click', function(e) {
            move_selection(e, this, OrderedSelectBox.move_all, field_id + '_to', field_id + '_from');
        });
        filter_input.addEventListener('keypress', function(e) {
            OrderedSelectFilter.filter_key_press(e, field_id);
        });
        filter_input.addEventListener('keyup', function(e) {
            OrderedSelectFilter.filter_key_up(e, field_id);
        });
        filter_input.addEventListener('keydown', function(e) {
            OrderedSelectFilter.filter_key_down(e, field_id);
        });
        selector_div.addEventListener('change', function(e) {
            if (e.target.tagName === 'SELECT') {
                OrderedSelectFilter.refresh_icons(field_id);
            }
        });
        selector_div.addEventListener('dblclick', function(e) {
            if (e.target.tagName === 'OPTION') {
                if (e.target.closest('select').id === field_id + '_to') {
                    OrderedSelectBox.move(field_id + '_to', field_id + '_from');
                } else {
                    OrderedSelectBox.move(field_id + '_from', field_id + '_to');
                }
                OrderedSelectFilter.refresh_icons(field_id);
            }
        });
        findForm(from_box).addEventListener('submit', function() {
            OrderedSelectBox.select_all(field_id + '_to');
        });
        OrderedSelectBox.init(field_id + '_from');
        OrderedSelectBox.init(field_id + '_to');
        // Move selected from_box options to to_box
        OrderedSelectBox.move(field_id + '_from', field_id + '_to');

        if (!is_stacked) {
            // In horizontal mode, give the same height to the two boxes.
            var j_from_box = $(from_box);
            var j_to_box = $(to_box);
            var resize_filters = function() { j_to_box.height($(filter_p).outerHeight() + j_from_box.outerHeight()); };
            if (j_from_box.outerHeight() > 0) {
                resize_filters(); // This fieldset is already open. Resize now.
            } else {
                // This fieldset is probably collapsed. Wait for its 'show' event.
                j_to_box.closest('fieldset').one('show.fieldset', resize_filters);
            }
        }
        // Initial icon refresh
        OrderedSelectFilter.refresh_icons(field_id);
    },
    refresh_icons: function(field_id) {
        var from = $('#' + field_id + '_from');
        var to = $('#' + field_id + '_to');
        var is_from_selected  = from.find('option:selected').length > 0;
        var is_to_selected    =   to.find('option:selected').length > 0;
        var is_from_non_empty = from.find('option').length > 0;
        var is_to_non_empty   =   to.find('option').length > 0;
        // Active if at least one item is selected
        $('#' + field_id + '_add_link').toggleClass('active', is_from_selected);
        $('#' + field_id + '_remove_link').toggleClass('active', is_to_selected);
        // Active if the corresponding box isn't empty
        $('#' + field_id + '_add_all_link').toggleClass('active', is_from_non_empty);
        $('#' + field_id + '_remove_all_link').toggleClass('active', is_to_non_empty);
    },
    filter_key_up: function(event, field_id) {
        from = document.getElementById(field_id + '_from');
        // don't submit form if user pressed Enter
        if ((event.which && event.which == 13) || (event.keyCode && event.keyCode == 13)) {
            from.selectedIndex = 0;
            OrderedSelectBox.move(field_id + '_from', field_id + '_to');
            from.selectedIndex = 0;
            return false;
        }
        var temp = from.selectedIndex;
        OrderedSelectBox.filter(field_id + '_from', document.getElementById(field_id + '_input').value);
        from.selectedIndex = temp;
        return true;
    },
    filter_key_down: function(event, field_id) {
        from = document.getElementById(field_id + '_from');
        // right arrow -- move across
        if ((event.which && event.which == 39) || (event.keyCode && event.keyCode == 39)) {
            var old_index = from.selectedIndex;
            OrderedSelectBox.move(field_id + '_from', field_id + '_to');
            from.selectedIndex = (old_index == from.length) ? from.length - 1 : old_index;
            return false;
        }
        // down arrow -- wrap around
        if ((event.which && event.which == 40) || (event.keyCode && event.keyCode == 40)) {
            from.selectedIndex = (from.length == from.selectedIndex + 1) ? 0 : from.selectedIndex + 1;
        }
        // up arrow -- wrap around
        if ((event.which && event.which == 38) || (event.keyCode && event.keyCode == 38)) {
            from.selectedIndex = (from.selectedIndex == 0) ? from.length - 1 : from.selectedIndex - 1;
        }
        return true;
    }
};
